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Encryption Library .NET Library

Encrypt, decrypt and hash data with industry standard encryption algorithms.

Features

  • Create one-way hashes to protect data such as user passwords.
  • Easily encrypt and decrypt sensitive data, such as credit card numbers, using industry standard symmetric algorithms.

One-way encryption, a.k.a. hashing

A common use of one-way encryption/hashing is to store sensative information such as passwords in a database. By hashing each user's password, and storing only that in the database, there is no risk of having passwords revealed should the database be compromised as there is no way to undo a hashed value back to the original value. When a user enters their password on a login page, the entered password is hashed and compared to the stored version (preferrably using a case-sensitive comparison). Because the hash of the password is being compared, the original, unencrypted password does not need to be stored anywhere.

Another use is to create checksums on files or data to ensure that the data has not been changed during transmission (e.g. over the internet). To do this, a hash of the data is generated and sent with the original data. On the receiving end, the receiver takes another hash of the data and compares the generated hash to the sent hash. If they are different, then the data has changed. To guard against intentional attacks where a third party has intercepted the data, changed it, and re-generated the hash, a 'salt' value can be used when generating the hash. A third party will only be able to modify the data undetected if they also know the 'salt' value. If the data being sent is private and requires encryption, then an alternative encryption technique is needed (see the symmetric Encryptor class).

One-way encryption live demo

Encrypting and decrypting, a.k.a. symmetric encryption

The Encrypter class is able to encrypt text or other data, and decrypt it back to plaintext. This class is suitable for storing private information such as credit card numbers in a database. In order to encrypt and decrypt data, the password, which is a GUID, must be supplied. Your application should store this GUID in a secure location, away from the location where the encrypted data is stored.

This class uses the 256 bit Rijndael Advanced Encryption Standard (AES) algorithm. This is an industry-standard algorithm, used by the US National Security Agency (NSA), who approved the use of the algorithm to encrypt classified information.